A model to simulate the contribution of fibre reinforcement for the punching resistance of RC slabs

In this paper analytical formulations are developed for the prediction of the punching resistance of flat slabs 17 of steel fibre reinforced concrete (SFRC) flexurally reinforced with steel bars. By performing statistical 18 analysis with a database that collects experimental results on the characterization of the post-cracking 19 behaviour of SFRC, equations are determined for the evaluation of the residual flexural tensile strength 20 parameters (fRi) from fundamental data that characterize steel fibres. The fRi strength parameters proposed by 21 CEB-FIP 2010 were used for the definition of the stress-crack width law (s-w) that simulates the fibre 22 reinforcement mechanisms in cement based materials. In the second part of the paper is described an 2 analytical formulation based on the concepts proposed by Muttoni and Ruiz, where 23 the s-w law is 24 conveniently integrated for the simulation of the contribution of steel fibres for the punching resistance of 25 SFRC slabs. By using a database composed of 154 punching tests with SFRC slabs, the good predictive 26 performance of the developed proposal is demonstrated. The good performance of this model is also 27 evidenced by comparing its predictions to those from other models.Fundação para a Ciência e a Tecnologia (FCT

Pancreatic Cancer Diagnosis and Management: Has the Time Come to Prick the Bubble?

Pancreatic cancer (PC) is associated with poor prognosis and very dismal survival rates. The most effective possibility of cure is tumor resection, which is only possible in about 15% of patients diagnosed at early stages of disease progression. Recent whole-genome sequencing studies pointed genetic alterations in 12 core signaling pathways in PC. These observations hint at the possibility that the initial mutation in PC might appear nearly 20 years before any symptoms occur, suggesting that a large window of opportunity may exist for early detection. Biomarkers with the potential to identify pre-neoplastic disease or very early stages of cancer are of great promise to improve patient survival. The concept of liquid biopsy refers to a minimally invasive sampling and analysis of liquid biomarkers that can be isolated from body fluids, primarily blood, urine and saliva. A myriad of circulating molecules may be useful as tumor markers, including cell-free DNA (cfDNA), cell-free RNA (cfRNA), circulating tumor cells (CTC), circulating tumor proteins, and extracellular vesicles, more specifically exosomes. In this review, we discuss with more detail the potential role of exosomes in several aspects related to PC, from initiation to tumor progression and its applicability in early detection and treatment. Exosomes are small circulating extracellular vesicles of 50–150 nm in diameter released from the plasma membrane by almost all cells and exhibit some advantages over other biomarkers. Exosomes are central players of intercellular communication and they have been implicated in a series of biological process, including tumorigenesis, migration and metastasis. Several exosomal microRNAs and proteins have been observed to distinguish PC from benign pancreatic diseases and healthy controls. Besides their possible role in diagnosis, understanding exosomes functions in cancer has clarified the importance of microenvironment in PC progression as well as its influence in proliferation, metastasis and resistance to chemotherapy. Increasing knowledge on cancer exosomes provides valuable insights on new therapeutic targets and can potentially open new strategies to treat this disease. Continuous research is needed to ascertain the reliability of using exosomes and their content as potential biomarkers, so that, hopefully, in the near future, they will provide the opportunity for early diagnosis, treatment intervention and increase survival of PC patients

The predictive performance of design models for the punching resistance of SFRC slabs in inner column loading conditions

In the recent years steel fibre reinforced concrete (SFRC), in a volume percentage between 0.75 and 1.25, is being proposed to build slabs supported on piles and slabs supported on columns, where the unique conventional reinforcement is composed of some steel bars in the alignments of the columns/piles, designated as anti-progressive collapse bars. Punching resistance, however, can be a concern in this structural system. In fact, punching has a brittle failure character, and the prediction of the punching resistance is still a challenge, even in concrete slabs with traditional reinforcement systems. The difficulties on assessing the contribution of the reinforcement mechanisms of steel fibres for the flexural and shear resistance in the critical punching perimeter increase this complexity. The research carried out in this paper has the purpose of assessing the reliability of existing analytical models for the prediction of the punching resistance of SFRC slabs. For this purpose, a data-base of experimental tests with SFRC slabs failing in punching was built and the predictive performance of four analytical available models was assessed. In order to turn more practical the model that is more reliable from physical and mechanical point of views, the concepts proposed by Model Code 2010 for the characterization of the postcracking behaviour of FRC were introduced in this model

Punching CFRP-based strengthening solutions for reinforced concrete flat slabs

This paper presents an experimental research program on the punching strengthening of flat reinforced concrete (RC) slabs with carbon fibre reinforced polymer (CFRP) systems. The strengthening system consists of CFRP wet layup sheets that are installed into holes opened orthogonally to the RC slab, and bonded to the surrounding substract with epoxy adhesive. Two different techniques were adopted: one where the CFRP system fully wraps two consecutive holes, forming a close type stirrup; the second is formed by a type of flexible CFRP bar installed into each hole, working like a dowel. The experimental program is composed of 12 real scale prototypes representative of RC slab-column connection (2500 × 2500 mm plan dimensions and 180 mm thickness). One of the prototypes was not strengthened for constituting the reference specimen, while the others were strengthened by adopting different arrangements for the strengthening systems, namely the pattern of the holes (cross versus radial), number of strengthening perimeters, holes per perimeter and CFRP cross sectional area per perimeter. A maximum increase of punching capacity of 67% was obtained by using the proposed strengthening techniques, having been possible to convert brittle punching failure into a ductile flexure one with the most effective punching strengthening configurationsCNPq, CAPES and FCT (project PTDC/ECM-EST/1882/2014) for funding support provided to the research activities, and BASF for supplying the strengthening systems for the experimental progra

Biofilms of Salmonella and Campylobacter in the Poultry Industry

Biofilm is characterized by a bacterial population firmly adhered to a surface involved by a self-produced matrix of extracellular polymeric substance. These communities provide longer survival and resistance to adverse conditions such as presence of antibiotics and disinfectants. Various foodborne microorganisms are capable of forming such structures, including Salmonella and Campylobacter, which are the major contaminants at the poultry industry. This biomass can affect the water transport system and pipes, and once the agent is established at the industry, it can form biofilms in any processing area. There are intrinsic and extrinsic mechanisms, and also molecular aspects involved in the biofilm formation. The adoption of several strategies may exhibit effectiveness to prevent the cell adhesion, such as the use of surfaces resistant to biofilm formation. In case of preexisting biofilms, there are physical, chemical, and biological methods used to control and eliminate them. Nanotechnology has emerged as another effective measure as nanometals affect the essential activities of microorganisms. These findings highlight the difficulty in controlling biofilms, due to the strategies used by these agents to adapt and survive in sessile form, causing recurring contamination throughout the poultry chain production, deterioration in the final product and infections in the human host

Avaliação do cálculo da resistência ao punçoamento centrado de lajes fungiformes reforçadas com fibras de aço : modelos teóricos

Desde 1979 que as fibras de aço vêm sendo estudadas como uma alternativa de reforço às estruturas de betão armado. No que diz respeito ao sistema estrutural de lajes fungiformes, os avanços conseguidos no campo da ciência dos materiais e das técnicas de construção já permitem a construção de estruturas onde as lajes são reforçadas praticamente apenas por fibras de aço. Para que este novo sistema construtivo possa competir com os métodos convencionais é necessário que os modelos teóricos que descrevem o complexo comportamento da ligação laje-pilar acompanhem a evolução destas técnicas construtivas. No entanto, ainda não existem regras de projeto que considerem a contribuição das fibras de aço na resistência ao punçoamento de lajes fungiformes. Com o intuito de contribuir para o aumento do conhecimento sobre o dimensionamento ao punçoamento centrado de lajes fungiformes de betão reforçado com fibras de aço (BRFA), o presente artigo apresenta e avalia o desempenho de quatro formulações semi-empíricas. Esse desempenho foi avaliado comparando-se os resultados previstos por cada modelo, Vteo, com as respostas experimentais, Vexp, de 154 lajes que compõem a base de dados (BD) construída para este efeito. As lajes da BD, além de terem rompido todas por punçoamento, também cobrem uma ampla faixa de resistência à compressão do betão, f c , de taxa de armadura de flexão, ρ, de altura útil das lajes, d, de percentagem volumétrica de fibras, Vf , e de esbelteza das fibras, L/D, em que L e D são o comprimento e o diâmetro da fibra. Além da avaliação da relação Vexp/Vteo, também foi avaliada a influência que os parâmetros f c , ρ, Vf e L/D exercem sobre a capacidade preditiva dos modelos considerados

Analysis of bond strength between a nylon reinforcement structure and dental resins

Nylon is a polymer that its use to reinforce dental resins has shown positive results such as increased flexural strength. The aim of this study was to evaluate the bond strength between dental resins and a nylon reinforcement. Forty cylindrical nylon

Community pharmacies and pharmacists in Brazil: A missed opportunity

The Brazilian National Health System (BR-NHS) is one of the largest public health systems in the world. In 2019 Brazil had 114,352 community pharmacies (76.8% private owned), that represent the first point of access to healthcare in Brazil due to their wide distribution. Unfortunately, from the government's point of view, the main expected activity of private and public community pharmacies is related to dispensing medicines and other health products. Public community pharmacies can be part of a healthcare center or be in a separate location, sometimes without the presence of a pharmacist. Pharmacists working in these separated locations do not have access to patients’ medical records, and they have difficulty in accessing other members of the patient care team. Pharmacists working in public pharmacies located in healthcare centers may have access to patients’ medical records, but pharmacy activities are frequently under other professional’s supervision (e.g., nurses). Private pharmacies are usually open 24/7 with the presence of a pharmacist for 8 hours on business days. Private community pharmacies have a very limited integration in the BR-NHS and pharmacists are the third largest healthcare workforce in Brazil with more than 221,000 registered in the Brazilian Federal Pharmacist Association [CFF - Conselho Federal de Farmácia]. A University degree in pharmacy is the only requirement to entry into the profession, without any proficiency exam for maintenance or career progression. The Brazilian pharmacist's annual income is ranked as the 2nd better-paid profession with an annual average income of € 5502.37 (in 2020). Description of clinical activities for pharmacies by the CFF increased in the recent years, however there is still a long way to effectively implement them into practice

Citotoxicity and acute oral toxicity tests of nanometer- and submicrometer-sized hollow spheres of chondroitin sulfate as a potential formulation strategy for anti-inflammatory encapsulation.

NanoAgri 2010. Editors: Caue Ribeiro, Odílio Benedito Garrido de Assis, Luiz Henrique Capparelli Mattoso, Sérgio Mascarenhas